For example, in continuous casting for steel, molten steel poured into a mold is cooled by a cooling means, whereby a solidified shell grows and a casting product is drawn from below the mold. Here, the casting product drawn from the mold is not completely solidified at the point in time when coming out of the mold but has an unsolidified portion therein. Therefore, there is a possibility that so-called bulging deformation of the casting product being deformed to bulge out occurs due to static pressure of the molten steel in the mold. The bulging deformation may cause internal defects such as center segregation and porosity in a width-direction center region of the casting product where the unsolidified portion is present.
To suppress the internal defects such as center segregation and porosity due to the bulging deformation, continuous casting equipment provided with a casting product reduction apparatus that applies pressure to long side surfaces of the casting product drawn from the mold is suggested, for example, in Patent Documents 1 and 2. Here, in the casting product reduction apparatus described in Patent Document 2, a casting product reduction roll in contact with the casting product is composed of divided rolls divided in an axial direction, and bearing parts that are arranged between divided rolls adjacent in the axial direction.
Here, since the unsolidified portion is present in the width-direction center region of the casting product, by applying reduction only to the width-direction center region of the casting product, even when the reduction load is reduced, it is possible to prevent the internal defects such as center segregation and porosity due to the bulging deformation.
Accordingly, for example, Patent Documents 3, 4, and 5 suggest methods and apparatuses for applying reduction to a casting product by use of casting product reduction rolls including a large-diameter part that projects radially outward in an axial-direction center region.